Treatment of textile materials



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utented Jan. 16, 1940 UNITED STATES PATENT TREATMENT OF TEXTILE MATERIALS of Delaware No Drawing. Application September 1'1, 1937, Serial No. 164,311

3 Claims.

This invention relates to the finishing of fabrics or yarns containing organic derivatives of cellulose to produce more stable materials and materials which are fast to light and acid fading.

ltn object of this invention is the economic and expeditious finishing of dyed fabrics and yarns containing an organic derivative of cellulose. dnother object of this invention is the finishing of dyed fabrics and yarns containing an organic derivative of cellulose in such a manner that they are more fast to light, acid and perspiration fading. Other objects of our invention will appear from the following detailed description.

it has been found that many dyed textile materials that contain an organic derivative of cellulose are subject to light and acid fading accomnanied by the development of less stable materials, that is, the filaments or fibers of the yarn become weaker, have a lower melting point and a lower viscosity when dissolved in a solvent. Many expedients have been used to correct this undesirable property, such as chemical treatment of the organicderivative of cellulose before dyeing and even before spinning, which treatments have greatly improved stability of the materials especially when they are not dyed. When dyed or given a normal finishing treatment stability of the material is decreased and continues to decrease with age and exposure. We have now found that if the textile materials, after the last wet treatment in finishing, are treated with a liquid containing a weakly ionized inorganic base that the stability is greatly improved and also the fastness of color of the dyed materials is improved.

in accordance with this invention, fabrics or other textile materials containing an organic derivative of cellulose are treated with a liquid such as an" aqueous solution or dispersion of a weakly ionized inorganic base. This treatment is preferably given the textile material right after the last wet finishing operation, such as, for example, a dyeing and scouring operation. The aqueous solution may contain some strongly ionized inorganic base such as sodium hydroxide, or potassium hydroxide, but in this case the percentage of weakly ionized inorganic base should be greater than that of the strongly ionized inorganic base. The weakly ionized inorganic base present may be just slightly more than the amount of strongly ionized inorganic base, or it may be two or three, or more, times in parts per million of the strongly ionized inorganic base present. This treatment is especially applicable to fabrics dyed with amino anthraquinone dyes but may be em- (cn. we

ployed with fabrics dyed with other dyestuffs or fabrics which have not been dyed. The treatment of undyed fabrics enhances the stability of the organic derivative of cellulose.

The fabrics that lend themselves to this invention are those formed substantially wholly of filaments or fibres of organic derivatives of cellulose. Fabrics of mixed yarns containing both filaments or fibres of organic derivatives of cellulose and other filaments or fibres, such as silk, cotton, etc., may be employed and the results will be proportional to the percentage of the yarn formed of organic derivatives of cellulose. The organic derivatives of cellulose may be the organic esters of cellulose or cellulose others, or mixed ethers esters of cellulose; Examples of the organic esters of cellulose are cellulose acetate, cellulose formate, cellulose propionate and cellulose butyrate, while examples of the cellulose ethers are ethyl cellulose, methyl cellulose and benzyl cellulose.

The fabric to be finished may be formed by weaving, warp-knitting, circular knitting, knotting or netting of. yarns of any degree of twist,

- which yarns contain at least some filaments or fibres of an organic derivative of cellulose. Although this invention is primarily applicable to fabrics, it may in an obvious manner be applied to yarns, straws, monofils, foils, etc. in hank or spool form. The filaments, fibres or yarns of organic derivatives of cellulose may contain, besides the cellulose derivatives, effect materials such as pigments, filling materials, dyes or lakes, fire retardants, plasticizers and lubricants. The reagents necessary to produce the desired properties obtained through the use of the effect materials are known to one practicing the art.

The organic derivative of cellulose base material may be made by any suitable method and, prior to its being formed into fibres or filaments, it may be treated with water or steam, with or without pressure, or given other types of stabilizing treatments. The fibres or filaments may be formed from a solution of the organic derivative of cellulose by either the wet or dry method of forming filaments and these fibres or filaments may be coated or otherwise treated with lubricants, sizes, etc. that may be necessary for their production into textile materials such as yarns and fabrics. The fibres or filaments may be processed in the usual manner to yarns and fabrics.

The fabrics containing organic derivative of cellulose yarns or filaments may be dyed in the usual manner with dyes having an affinity therefor or they may be partially saponified and dyed with cotton colors. The fabrics may be scoured, delustered and given other treatments normally applied during finishing operations of the various types of fabrics, except that after the last wet finishing operation they are treated with a liquid containing a weakly ionized inorganic base. In one modification of our invention it is preferable to dye the textile material in a dye bath containing a small amount of a tertiary amine having at least two aryl substitution groups, such as, for example, benzyl ethyl aniline, diphenyl aniline, phenyl ethyl aniline, dibenzyl aniline, etc. Organic derivatives of cellulose have the property of absorbing small amounts of this material from the dye bath, which material they retain through the washing and securing operations which follows.

The liquid with which the textile materials are to be treated in accordance with this invention is preferably water in which is dissolved or colloidally dispersed a weakly ionized inorganic base such as an oxide, hydroxide or the carbonate of an alkali earth metal, or similar weakly ionized inorganic bases. We have found that a liquid base consisting substantially of water and calcium hydroxide is to be preferred. The treating liquid may be made by dissolving or dispersing from 2 to 0.05 grams per liter of a weakly ionized inorganic base in water. Where the water contains or is to contain strongly ionized inorganic bases such as potassium hydroxide, sodium hydroxide, ammonia, etc., sufilci-"nt of the weakly ionized inorganic base may be added to more than counter-act the strongly ionized inorganic base. For instance, water containing sufiicient highly ionized inorganic bases to form to parts per million of soft soap requires sufi'icient of the weakly ionized inorganic base material to form to or more parts per million of a hard soap.

After the textile material is treated in accordance with this invention it may be hot or cold calendered, steamed, tentered, ironed or otherwise dry finished and packaged for use.

Any method of applying the treating liquid to the textile material may be employed such as spraying the liquid onto the material or by immersing the material in the liquid. It is preferable that the material be completely wetted with theliquid and still more preferable that the material be treated with from 10 to 30 times its weight of the liquid. However, with stronger concentration of the weakly ionized inorganic base material lesser amounts of treating liquid need be employed. Concentrations of above 2 grams per liter may be employed but for most purposes should be avoided. Fabrics may be padded with the treating liquid on any suitable padding device or on one as described in U. S. application S. No. 123,102 filed January 30, 1937. The fabric may be treated while on a jig of any suitable construction or on one as described in U. S. Patent No. 2,069,311. The temperature of the treating bath may vary from 20 C. to 85 C. or more. It is preferable, however, to have the treating bath at about 60 C. at the time the material is entered therein.

As an illustration of our invention, but without being limited thereto, the following example is given:

Example Textile material consisting of cellulose acetate is dyed in a dye bath containing 2% of benzyl ethyl aniline on the weight of the cellulose acetate. This material after being dyed to the desired shade is separated from the dye bath, rinsed, secured in the soap solution and again rinsed. The rinsed material is then treated with 30 times its weight of a liquid consisting of substantially pure water and 0.1 gram per liter of calcium hydroxide. The fabric is then dried in the usual manner. The fabric is found to be greatly improved in stability insofar as any change in the cellulose acetate is concerned, and there is also found to be a great improvement in the fastness to light and acid fading of the color imparted thereto.

It is to be understood that the foregoing detailed description is merely given by way of illustration and that many variations may be made therein without departing from the spirit of our invention.

Having described our invention, what we desire to secure by Letters Patent is:

1. In a process for finishing dyed textile materials containing filaments or fibers of an organic derivative of cellulose so as to cause said dyed materials to be made fast to light, acid and perspiration fading, the step of treating said dyed textile material, after the final wet finishing treatment, with calcium hydroxide, whereby the calcium hydroxide is incorporated in said dyed textile material.

2. In a process for finishing dyed textile materials containing filaments or fibers of cellulose acetate so as to cause said dyed materials to be made fast to light, acid and perspiration fading, the step of treating said dyed textile material, after the final wet finishing treatment, with an aqueous liquid containing from 2.0 to 0.05 grams per liter of calcium hydroxide whereby the calcium hydroxide is incorporated in said dyed textile material.

3. In a process for finishing dyed textile materials containing filaments or fibers of cellulose acetate so as to cause said dyed textile materials to be made fast to light, acid and perspiration fading, the steps of dyeing the material in a dye bath containing a tertiary amine having at least two aryl substitution groups, separating the material from the dye bath and treating it, after the final wet finishing treatment with a liquidcontaining calcium hydroxide, whereby the calcium hydroxide is incorporated in the dyed textile material.

GEORGE SCHNEIDER. WILLIAM WHITEHEAD. 

